SU890275A2 - Device for checking break and short curcuit in electromagnetically loaded circuit - Google Patents

Description

one

The invention relates to electrical engineering, in particular, to devices that monitor the state of targets containing an electro-magnetic load.

According to the main auth. No. 528515, a device for monitoring an open circuit and a short circuit in an electromagnetic load circuit is known, comprising a series-connected AC test voltage source, a diode, a pilot signal connection unit, an operating signal switching unit and a DC operating voltage source, a second diode connected with a relay connected in parallel. A control and a capacitor, in parallel with which a load is connected, is connected to the switching unit of the operating signal. The known device allows to control a circuit containing an electromagnetic load for the presence of an open circuit and a short

short-circuits. At the same time, the output of the device generates signals corresponding to an operable and faulty Cl circuit.

A disadvantage of the known device is that the type of fault is not determined.

The aim of the invention is to expand the functionality.

ten

The goal is achieved by the fact that the device for controlling an open circuit and a short circuit in an electromagnetic load circuit, containing an operating signal switching unit connected to a direct current voltage source, the output of which is connected to an electromagnetic load, a control signal connecting unit connected through a diode

Claims (2)

20 with a control current source of alternating current and an electromagnetic control relay, the winding of which is bridged by a capacitor, is switched through a second diode parallel to the electromagnetic load, the control signal connection unit is connected parallel to the operating signal switching unit, and the second diode. One in the control relay circuit is connected in opposition to the first diode, a block for determining the nature of the fault and a resistor are inserted, with the output of the block. connecting the control signal is connected to the electromagnetic load through a resistor, the terminals of which are connected to the inputs of the block for determining the nature of the fault. In this case, the malfunction characterization unit contains a ZK-trigger comparator and an AND element, the comparator inputs are connected to the inputs of the malfunction characterization block, the comparator output is connected to the 3K-trigger input and the first input of the And element, the second input of which is connected with the output of the K-trigger, and the output of the element I is connected to the output of the unit for determining the nature of the malfunction. In this scheme, the combination of the signal at the outputs of the control unit and the unit for determining the type of fault determines the nature of the fault. In addition, the use of a resistor excludes a short circuit for the control voltage source. The drawing shows a diagram of the device. The device contains a source of DC operating voltage, an operating signal switching unit 2, an AC test voltage source 3, a pilot signal connection unit k, an electromagnetic load 5, a diode 6, a control unit 7 | consisting of a control relay 8, capacitor 9, diode 10, resistor 1 1, block 12 for determining the nature of the fault, consisting of com-, parator 13) 3K flip-flop 14 and element 15 I. Source of control signal through diode 6, block C connecting the control signal and resistor 11 is connected in parallel flax electromagnetic load. Parallel to the resistor, a comparator input is connected, the output of which is connected to the first input of the And element and to the control input of the ZK trigger. The trigger output is connected to the ethereal input of the edentum I. 8 4 The device operates as follows. When an alternating voltage is supplied from a source 3 to a controlled circuit by an electromagnetic load, in case of a working circuit, the relay 8 of the control is triggered, and the contacts of the relay 8 form at the output of the control unit a signal corresponding to the reference state of the circuit. If the monitored circuit breaks, the relay 8 does not work, the output of the control unit is a signal corresponding to the faulty circuit, and there is no signal at the output of the malfunction detection unit, which corresponds to an open circuit in the circuit under control. 3, a K-trigger 14 is inputted at the trailing edge of the first pulse from the comparator output. Therefore, through the AND element, all impulses from the comparator output, with the exception of the first, arrive at the output of the node determining the type of malfunction. This is necessary to prevent the occurrence of a spurious signal of the presence of a short circuit in the case of an operable circuit, since the control relay 8 is triggered by the emf of self-induction arising in the electromagnetic load 5 on a given front of the first half-period of the control signal from source 3. Before the control checks start 14 must be reset. The use of the present invention makes it possible to detect not only the presence of a fault in a circuit with an electromagnetic load, but also to determine the nature of this fault. Claim 1. Device for monitoring open circuit and short circuit in circuit with electrically, romagnetic load according to author. No. 528515, characterized in that, in order to expand its functionality, a malfunction detection unit and a resistor are inserted into it, the output of the pilot signal connection unit is connected to the electromagnetic load through a resistor, the terminals of which are connected to the inputs of the malfunction detection unit. 5890275 2. A device according to nl, which is based on the fact that the block for determining the nature of the malfunction contains a comparator, a TC trigger and the element I, the inputs of the comparator are connected to the inputs of the block for determining the nature of the malfunction, the output the comparator is connected to the input} of the K-flip-flop and the first input of the element I, the second input of which is connected to the output of the K-flip-flop, and the output of the element I is connected to the output of the block for determining the nature of the fault. Sources of information taken 80 attention in the examination 1. USSR author's certificate No. 528515, cl. G 01 R 31/02. 1973 (prototype).